A factoid about which there is a surprising amount of agreement,E with respect to ethics, is the proposition of supervenience in ethics. For an introductory slogan:
- A supervenes on B if and only if A is different only when B is different.
Ethics-wise:
... to adapt R. M. Hare’s canonical example (1952, §5.2), if I mentioned to you that one possible act was right, and another wrong,🏰 despite these acts being exactly alike in all other respects, your initial reaction would be puzzlement, and if I persisted in my view upon interrogation, you might start to worry that I was simply confused or misusing words.
Your question, then, can be interpreted as asking about the supervenience of the physical on the ethical: does this ever happen? Or would it be required to happen, to have the kind of vividly realistic moral ontology you're asking about?
Historically, the prime example of this notion is "ought implies can" (see the PhilPapers list of papers having to do with this topic).𝕬 In Kant's hands, this precept has the metaphysical "oomph" that is enough to compromise the thesis of universal empirical determinism, such as to say that something can be recognized as possible not because antecedent empirical conditions make it so, but on account of our moral ontology:
Suppose some one asserts of his lustful appetite that, when the desired object and the opportunity are present, it is quite irresistible. [Ask him] if a gallows were erected before the house where he finds this opportunity, in order that he should be hanged thereon immediately after the gratification of his lust, whether he could not then control his passion; we need not be long in doubt what he would reply. Ask him, however: if his sovereign ordered him, on pain of the same immediate execution, to bear false witness against an honourable man, whom the prince might wish to destroy under a plausible pretext, would he consider it possible in that case to overcome his love of life, however great it may be. He would perhaps not venture to affirm whether he would do so or not, but he must unhesitatingly admit that it is possible to do so. He judges, therefore, that he can do a certain thing because he is conscious that he ought, and he recognizes that he is free—a fact which but for the moral law he would never have known.
If you mix this with a modal-epistemology claim that we can actually perceive possibilities, then you might have an example of a perceptible sample of your proposed moral ontology. (Note: if your modal epistemology is coming all the way from Kant, however, this won't do: for Kant did not think that we could blatantly "perceive" modal predicates in such a manner, at least not on my reading of him.)
EThere is much less agreement when it comes to the notion of "moral explanations." But the topic is relevant to your inquiry, and so as they say in the linked-to SEP entry:
... [It is claimed that] sometimes a moral truth is necessary for the best explanation of a non-moral fact (cf. Sturgeon 1985). Hitler’s vices are sometimes cited to explain his atrocities. Slavery’s injustice has been said to explain its demise. And the fact that everyone agrees that it is morally wrong to torture babies just to get sexual pleasure might be best explained by the fact that this common belief is true.
🏰One might object that Hare chose his divergence on the basis of too harsh a contrast, that between right and wrong, which are opposites. It seems strange to think that a normal object could sustain this contrariety even if the issue of supervenience has not arisen. But suppose instead that you were told of two tokens t of some action-type that t1 was good and t2 was neutral, or t1 was optional but not indifferent whereas t2 was just indifferent, etc. Arguably, these cases of non-supervenience should offend our intuitions less than the right-vs.-wrong kind of case would.
𝕬In Anselm's hands, "ought implies can" is taken to be so powerful that it can adjust possibilities having to do with the divine nature itself (see his Wherefore the God-man, usually Cur Deus Homo). Specifically, Anselm thinks OiC allows us to logically-consistently say that there could be, because there should be, a personal being who somehow "has" two radically separate natures (a mortal and an eternal one). Granted, this has next to nothing to do with scientifically detecting the impact of a robust moral ontology, on the human world, since one could not scientifically decide whether some human being ever "had" the divine nature, via their personhood, "on the side" (indeed, one will probably never scientifically perceive such a nature).